Document performance-relevant settings

[appgurueu]

Excerpts from a recent conversation on Discord:

A: is there a way to make minetest use more system resources and output a higher framerate

[...]

B: for users, the closest setting i can think of, if you have a beefy GPU, is the client_mesh_chunk setting

[...]

A: that actually helps a lot. set it to 3 and nearly quadrupled framerate

It would be helpful to document this on a separate page, along with other settings which are relevant for performance, such as transparency_sorting_distance. Should probably be split into "client" and "server".

[wsor4035]

<insert rubens forum post about client_mesh_chunk + server settings for longer rendering range>

edit: https://forum.luanti.org/viewtopic.php?t=29266

[mark-wiemer]

There is a lot of talk about client vs server. Personally I don't really know the difference. Maybe I'm dumb, but I'd suggest a quick intro to what is handled client-side vs server-side, how much of that is relevant when playing single-player, etc. Might be worth a new issue, or maybe there are already docs, lol. Just writing this down before I forget